Owing to the ongoing development of mobile environments, it becomes unnecessary for a patient to go to the doctor. Instead, a patient's status is monitored anytime and anywhere and the monitored information is then forwarded to a hospital by real time to provide the patient with an appropriate medical service. Thus, as the appropriate medical services can target ordinary people to manage user's health anytime and anywhere. This U-health network industry is rising as a new growth industry and can provide each individual with sustainably safe life as well as with convenience, comfortableness, time saving, cost reduction and the like.
MBAN (medical wireless body area network) can be sorted into In-body type for monitoring a device implanted in a human body from an outside of the human body due to in-body propagation property and On/Out-body short-range communication type for monitoring a device attached to or provided outside a human body to detect an effect generated from a human body surface or around a human body in 3 to 5 meters.
MICS (medical implant communications system) of the in-body type provides interactive digital communications between active medical implant transceivers provided in and out of a human body. Currently, millions of people live by depending on the active medical implant devices globally. And, the active medical implant devices cover a wide scope of medical treatment functions including heartbeat control, pain control, medication, urinary incontinence control, diabetic insulin control device, implanted medication injection device and the like.
MBAN system is devised to provide a flexible platform for wireless networking of a multitude of sensors used to monitor patient's physiological data in health care facility such as a hospital and the like. The MBAN system operates on 2,360˜2,400 MHz. Maximum emission bandwidth is limited to 5 MHz. Transmission power amounts to a smaller one of 1 mW and 10*log(B) dBm in case of operation on 2,360˜2,390 MHz. In this case, ‘B’ indicates 20-dB emission bandwidth. In case of operation on 2,390˜2,400 MHz, a smaller one of 20 mW and 10*log(B) dBm is used as a transmission power. In this case, ‘B’ indicates 20-dB emission bandwidth.
2,360˜2,400 MHz corresponds to a frequency band assigned for another wireless communication system in advance. And, the MBAN system operates on a secondary basis based on cognitive radio. In particular, harmful interference should not be caused to a primary user and interference generated form the primary user should be accepted in use.
To this end, in case of operation on a band of 2,360˜2,390 MHz in MBAN, MBAN devices (or terminals) should basically operate in an indoor space of a registered health care facility. A use of 2,360˜2,390 MHz should be controlled through cooperation with a primary user. When the primary user uses the corresponding band, all operations on this band should be initialized and an operation should be resumed using a new band of 2,390˜2,400 MHz.
When MBAN devices move outside, they should stop operating or perform transmissions by changing a transmission band into the 2,390˜2,400 MHz band used as a basic band. In case of operating on 2,390˜2,400 MHz, the MBAN devices are usable irrespective of an indoor space or an outdoor space. Therefore, in order to use a channel efficiently, it is necessary to select a channel according to mobility of an MBAN device.